It's currently possible to move methods to a superclass, or even create a new superclass with selected methods. How about providing the same thing, but without the class hierarchy? If most people coding patterns are similar to mine, this would be imensely useful. It goes like this...
Suppose I have to code some complex functionality. On a first step, I'll just write down what the code is supposed to do, on a huge method. On a second step, I'll break up this big method on smaller, more focused and easier to understand methods, and thankfully IDEA makes this a breeze. On a third step, I find out that a number of the extracted methods aren't exactly core concerns and could be moved to a helper class. Data access usually falls in this category.
Unfortunately, IDEA doesn't help me on this first step. I have to create the helper class manually, copy the methods over to the new class, and create a depenency on it in the old class. It would be really, really nice if IDEA could do this for me.